INCOMING CONNECTION SYSTEM OF PRIVATE BRANCH EXCHANGE

摘要

PURPOSE:To connect an automatic incoming call, which should be connected with a machine language, to an extensin subscriber automatically without passing an attendant board by discriminating the incoming call of a special terminal to start a controller when a central office line originating and terminating trunk receives this incoming call and connecting the incoming call to the special terminal by the controller. CONSTITUTION:When a call comes from a service office with the slave number of a special terminal 6b, the service office and a central office line originating and terminating trunk 9b are connected. The trunk 9b receives and discriminates a starting signal of the special terminal by its start receiving circuit and starts a common controller 13b through a trunk marker connector 17. The common controller 13b selects the special terminal 16b by the incoming class extracting function and discriminates whether it is busy or not. The special terminal 16b and the trunk 9b are connected through a main link 15 if it is not busy, but busy information is transmitted to the trunk 9b if it is busy. With respect to a general sounding incoming such as a group pilot incoming or the like, the call is connected from the trunk 9b to an attendant board (ATT) 11 through a position equipment (POS) 10, and a server of the attendant board 11 connects it to the extension telephone set of a called subscriber.